This invention relates to harmonicas or mouth organs and specifically to situating check valves within the comb of a harmonica. A previous patent incorporated check valves mounted on valve platforms, external to the reed plates of the harmonica, to improve musical range and volume. In this invention, check valves are mounted over slots situated internally between the mouth and the reeds to provide further improvements in performance and tonality. The central cells may be called valve cells. Employing a single internal valve cell in place of two external valve cells improves airtight performance, permits all reeds to be situated externally to the comb where their vibration is in direct contact with the outside air and simplifies construction by reducing the required number of components.
Check valves, or reed valves, are commonly used in the reed cells of harmonicas to improve performance. Reed valves are typically installed to control the flow of air within the harmonica. A reed valve, when attached to the external side of a reed slot to which an exhale-actuated or blow reed is secured, will serve to prevent inhaled air from passing by the blow reed when an inhale-actuated or draw reed associated with the same mouthpiece opening is being played. Likewise, a reed valve, when attached to the opposing side of a reed slot to which a draw reed is secured, will serve to prevent exhaled air from passing by the draw reed when a blow reed associated with the same mouthpiece opening is being played. For low-pitched and mid-range reeds the benefit of reduced air loss provided by reed valves outweighs the negative effects of their close proximity to the reeds. However, the amount of air that can be prevented from passing through the relatively small and constricted reed slots of high-pitched reeds, while considerable, may not be enough to outweigh the negative proximity effects of reed valves. For this reason, reed valves are usually omitted from the highest-pitched reeds of harmonicas incorporating reed valves.
U.S. Pat. No. 5,367,937 disclosed the use of one or more valve cells separate from the reed cell of the harmonica. In this patent, check valves were mounted external to the reed plates and the reeds. One embodiment of ""937 disclosed two valve cells associated with each mouthpiece opening, situated externally from the mouth, reed cell and reed plates.
In ""937, as air is exhaled into the harmonica, the blow valve cells and blow valves permit exhaled air to flow past the blow reeds and blow enabler reeds while, at the same time, exhaled air is prevented from flowing past the draw reeds and draw enabler reeds by the draw valve cells and draw valves. The draw valve cells and draw valves function to permit inhaled airflow past the draw reeds and draw enabler reeds while, at the same time, the blow valve cells and blow valves prevent inhaled airflow past the blow reeds and blow enabler reeds.
The design of the harmonica disclosed in ""937 requires the construction of three separate bodies to be assembled with two reed plates. These three bodies, defined in U.S. Pat. No. ""937 as the comb, blow platform, and draw platform, are essentially three separate combs. Comparing the harmonica of ""937 to a prior art harmonica that has a comb but no valve platforms, this design would be relatively expensive to produce, both in tooling and assembly costs. Furthermore, the four interfaces that occur between the comb, blow platform, draw platform, and each reed plate create a significant area susceptible to air loss. A standard harmonica, having only two interfaces between the comb and two reed plates, is significantly less liable to air loss than the harmonica of U.S. Pat. No. ""937. As the harmonica of U.S. Pat. No. ""937 is played, air losses through any of the four existing interfaces result in decreased volume and performance. Placement of the external valve cells between the reeds and the outside air, as disclosed in U.S. Pat. No. ""937, also reduces the amplitude of the overtones of the vibrating reeds. Because players can reduce the amplitude of the overtones of vibrating reeds when desirable by cupping the harmonica with their hands, but cannot increase the amplitude of the overtones of the vibrating reeds in a similar manner, harmonicas producing resonant overtones are generally preferred over harmonicas lacking in resonant overtones.
The disadvantages of harmonicas having check valves located between the reeds and the outside air are:
(a) The close proximity of reed valves to reeds in standard chromatic and standard diatonic harmonicas causes a reduction of volume and resonance, particularly with high-pitched reeds.
(b) A harmonica incorporating external valve cells, requiring three combs instead of one, can be expensive to produce compared to harmonicas with no external valve cells and one comb.
(c) A harmonica incorporating external valve cells is subject to high air loss compared to harmonicas with no external valve cells.
(d) A harmonica incorporating external valve cells produces a tonality deficient in resonant overtones compared to harmonicas with no external valve cells.
U.S. Pat. No. 5,367,937 disclosed the use of check valves mounted on valve platforms thereby creating two types of external valve cells, or valve cells external to the comb and reed plates of the harmonica, associated with each central cell, to improve musical range and volume. The first set of valve cells, the blow valve cells, contained valves that were actuated when air was blown into the harmonica. The second set of valve cells, the draw valve cells, contained valves that were actuated when air was inhaled from the harmonica.
In the present invention, check valves are mounted over slots situated between the mouth and the reeds, thereby creating internal valve cells, or valve cells within the comb, to provide further improvements in performance and tonality. Employing a single internal valve cell in place of two external valve cells improves airtight performance, permits all reeds to be situated externally to the comb where their vibration is in direct contact with the outside air and simplifies construction by reducing the required number of components.
Accordingly, several objects and advantages of this invention are:
(a) To reduce the negative tonal effects of reed valves in standard chromatic and diatonic harmonicas by removing them from close proximity to the reeds.
(b) To lower the production cost of harmonicas incorporating valve cells.
(c) To reduce the amount of air loss in harmonicas incorporating valve cells.
(d) To increase the resonance of the overtones in harmonicas incorporating valve cells.